Insanity is doing the same thing and expecting a different outcome and although the 10 plaques were a bit different the outcome always was lousy for the Egyptian people. Others might claim Pharaoh was just stubborn to the extreme but could a bit of insanity leap into his mind as well. Yet if he was insane could he punished for his crime? I believe G-D gives even those with significant difficulties paths to get through and just like Pharaoh if those paths are ignored they become less visible if you keep going in the opposite direction. We can help those with such problems to see the light but they themselves must be willing to open their own eyes.